A user enters a Billing Issue when Apple is failed to charge him. It's a flag for you that something is wrong with charges, it can be:
If you don't have a Grace Period for your in-app subscriptions a user will immediately lose access to the app's paid features.
Apple/Google will let you know about Grace Periods via server2server notifications. Handle, store and process them to build custom views with Grace Period's analytics.
It's also important to calculate both a number of events of issues and a number of users in a Billing Issue state as it'll affect your app Revenue.
Adapty get information about Billing Issue both on Event and User level for your apps automatically. Just install SDK and you're ready to go.
